"She was still trapped when police arrived at the scene and she died shortly afterwards, I think prior to even being able to be freed.''
He said it was too early to determine the cause of the crash, however speed and alcohol were not believed to be factors.
The two occupants of the light truck escaped the crash uninjured, he said.
He said ambulance, fire and police were called to the scene. Police were still in attendance and the Serious Crash Unit were on their way to the site, he said.
The death would be referred to the coroner, he said.
Diversions were in place around the scene, but a couple of lanes around the crash scene were expected to open up later today, he said.
The State Highway was the main route up the West Coast of the North Island, and was fairly heavily used by motorists, he said: "It's quite a busy stretch of road, and I understand it's quite busy there today.''
Holiday accidents claimed the lives of two others in separate accidents this morning.
One driver died in an accident on Waiuku Rd, between Wily and Titi Road at about 8am this morning.
Police said the driver of the car which drifted off a road south of Auckland was killed when the vehicle hit a totara tree and flung the driver from the vehicle.
Diversions are in place on Wily, Hill and Masters roads.
Earlier this morning, one person died after their car ran into the Avon River off New Brighton Road in Christchurch, shortly after 4am.
Fire, ambulance and police were called to the scene.
Neither the age or sex of the dead person has been released.
Police have also been attending a two car collision on SH1 in Kawakawa in the Far North.
The two vehicles involved were travelling at opposite direction and one appears to have veered onto the path of the other.
One vehicle has ended up in the ditch, the other came to rest on the southbound lane blocking the flow of traffic.
One passenger has suffered critical injuries, unknown what they are at this time. Four others suffered moderate injuries. All are being taken to the Bay of Islands hospital by ambulance.
The one lane open is being used to filter traffic through in both directions although its anticipated both lanes will be open again by 6pm. A traffic backlog has built up and motorists are asked to be patient and exercise caution.
Motorists are asked as well to avoid this area if at all possible.
